From: Jeff Dike <jdike@addtoit.com>
Date: Sat, 3 Sep 2005 22:57:33 +0000 (-0700)
Subject: [PATCH] uml: mark SMP on UML/x86_64 as broken
X-Git-Tag: v2.6.14-rc1~803
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=02edeb586ae4cdd17778923674700edb732a4741;p=platform%2Fkernel%2Flinux-exynos.git

[PATCH] uml: mark SMP on UML/x86_64 as broken

Noticed by Al Viro <viro@parcelfarce.linux.theplanet.co.uk> - SMP on x86_64 is
fundamentally broken due to UML's reuse of the host arch's percpu stuff.  This
is OK on x86, but the x86_64 pda stuff just won't work for UML.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/arch/um/Kconfig b/arch/um/Kconfig
index d5e22f0..684e1f8 100644
--- a/arch/um/Kconfig
+++ b/arch/um/Kconfig
@@ -196,7 +196,7 @@ config HOST_2G_2G
 config SMP
 	bool "Symmetric multi-processing support (EXPERIMENTAL)"
 	default n
-	depends on MODE_TT && EXPERIMENTAL
+	depends on (MODE_TT && EXPERIMENTAL && !SMP_BROKEN) || (BROKEN && SMP_BROKEN)
 	help
 	This option enables UML SMP support.
 	It is NOT related to having a real SMP box. Not directly, at least.
diff --git a/arch/um/Kconfig.x86_64 b/arch/um/Kconfig.x86_64
index 6e5357c..bd35e59 100644
--- a/arch/um/Kconfig.x86_64
+++ b/arch/um/Kconfig.x86_64
@@ -37,3 +37,7 @@ config ARCH_HAS_SC_SIGNALS
 config ARCH_REUSE_HOST_VSYSCALL_AREA
 	bool
 	default n
+
+config SMP_BROKEN
+	bool
+	default y